#include <bits/stdc++.h>
using namespace std;
int main(){
  int N;
  cin >> N;
  vector<int> P(N);
  for (int i = 0; i < N; i++){
    cin >> P[i];
    P[i]--;
  }
  int ans = 0;
  vector<bool> used(N, false);
  for (int i = 0; i < N; i++){
    if (!used[i]){
      used[i] = true;
      int v = i;
      while (true){
        v = P[v];
        if (used[v]){
          break;
        }
        used[v] = true;
        ans++;
      }
    }
  }
  cout << ans << endl;
}